This invention relates to a nucleic acid molecule which codes for a tumor rejection antigen precursor. More particularly, the invention concerns genes, whose tumor rejection antigen precursor is processed, inter alia, into at least one tumor rejection antigen. The tumor rejection antigen precursors in question do not appear to be closely related to other known tumor rejection antigen precursor coding sequences, and were isolated from the Xp region of human X chromosomes, in contrast to the genes to which they are most closely related, which were found on the Xq region. These newly isolated genes are members of the MAGE-B family, while those in the Xq region are now considered to be members of the MAGE-A family.
The process by which the mammalian immune system recognizes and reacts to foreign or alien materials is a complex one. An important facet of the system is the T lymphocyte, or xe2x80x9cT cellxe2x80x9d response. This response requires that T cells recognize and interact with complexes of cell surface molecules, referred to as human leukocyte antigens (xe2x80x9cHLAxe2x80x9d), or major histocompatibility complexes (xe2x80x9cMHCsxe2x80x9d), and peptides. The peptides are derived from larger molecules which are processed by the cells which also present the HLA/MHC molecule. See in this regard Male et al., Advanced Immunology (J. P. Lipincott Company, 1987), especially chapters 6-10. The interaction of T cells and HLA/peptide complexes is restricted, requiring a T cell specific for a particular combination of an HLA molecule and a peptide. If a specific T cell is not present, there is no T cell response even if its partner complex is present. Similarly, there is no response if the specific complex is absent, but the T cell is present. This mechanism is involved in the immune system""s response to foreign materials, in autoimmune pathologies, and in responses to cellular abnormalities. Much work has focused on the mechanisms by which proteins are processed into the HLA binding peptides. See, in this regard, Barinaga, Science 257: 880 (1992); Fremont et al., Science 257: 919 (1992); Matsumura et al., Science 257: 927 (1992); Latron et al., Science 257: 964 (1992).
The mechanism by which T cells recognize cellular abnormalities has also been implicated in cancer. For example, in PCT application PCT/US92/04354, filed May 22, 1992, published on Nov. 26, 1992, and incorporated by reference, a family of genes is disclosed, which are processed into peptides which, in turn, are expressed on cell surfaces, which can lead to lysis of the tumor cells by specific CTLs cytolytic T lymphocytes, or xe2x80x9cCTLsxe2x80x9d hereafter. The genes are said to code for xe2x80x9ctumor rejection antigen precursorsxe2x80x9d or xe2x80x9cTRAPxe2x80x9d molecules, and the peptides derived therefrom are referred to as xe2x80x9ctumor rejection antigensxe2x80x9d or xe2x80x9cTRAsxe2x80x9d. See Traversari et al., Immunogenetics 35: 145 (1992); van der Bruggen et al., Science 254: 1643 (1991), for further information on this family of genes. Also, see U.S. patent application Ser. No. 807,043, filed Dec. 12, 1991, now U.S. Pat. No. 5,342,774, incorporated by reference in its entirety. The xe2x80x9cMAGExe2x80x9d family of tumor rejection antigen precursors is disclosed in this patent.
In U.S. patent application Ser. No. 938,334, now U.S. Pat. No. 5,405,940, Apr. 15, 1995, the disclosure of which is incorporated by reference, it is explained that the MAGE-1 gene codes for a tumor rejection antigen precursor which is processed to nonapeptides which are presented by the HLA-A1 molecule. The nonapeptides which bind to HLA-A1 follow a xe2x80x9crulexe2x80x9d for binding in that a motif is satisfied. In this regard, see e.g. PCT/US93/07421; Falk et al., Nature 351: 290-296 (1991); Engelhard, Ann Rev. Immunol. 12: 181-207 (1994); Ruppert et al., Cell 74: 929-937 (1993); Rxc3x6tzschke et al., Nature 348: 252-254 (1990); Bjorkman et al., Nature 329: 512-518 (1987); Traversari et al., J. Exp. Med. 176: 1453-1457 (1992). The references teach that given the known specificity of particular peptides for particular HLA molecules, one should expect a particular peptide to bind to one HLA molecule, but not to others. This is important, because different individuals possess different HLA phenotypes. As a result, while identification of a particular peptide as being a partner for a specific HLA molecule has diagnostic and therapeutic ramifications, these are only relevant for individuals with that particular HLA phenotype. There is a need for further work in the area, because cellular abnormalities are not restricted to one particular HLA phenotype, and targeted therapy requires some knowledge of the phenotype of the abnormal cells at issue.
In U.S. patent application Ser. No. 08/008,446, filed Jan. 22, 1993 now abandoned and incorporated by reference, the fact that the MAGE-1 expression product is processed to a second TRA is disclosed. This second TRA is presented by HLA-Cw*1601 molecules. The disclosure shows that a given TRAP can yield a plurality of TRAs, each of which will satisfy a motif rule for binding to an MHC molecule.
In U.S. patent application Ser. No. 994,928, filed Dec. 22, 1992, now abandoned and incorporated by reference herein teaches that tyrosinase, a molecule which is produced by some normal cells (e.g., melanocytes), is processed in tumor cells to yield peptides presented by HLA-A2 molecules.
In U.S.; patent application Ser. No. 08/032,978, filed Mar. 18, 1993, now U.S. Pat. No. 5,620,886 and incorporated by reference in its entirety, a second TRA, not derived from tyrosinase is taught to be presented by HLA-A2 molecules. The TRA is derived from a TRAP, but is coded for by a non-MAGE gene. This disclosure shows that a particular HLA molecule may present TRAs derived from different sources.
In U.S. patent application Ser. No.08/079,110, filed Jun. 17, 1993 and incorporated by reference herein, an unrelated tumor rejection antigen precursor, the so-called xe2x80x9cBAGExe2x80x9d precursor is described. The BAGE precursor is not related to the MAGE family.
In U.S. patent applications Ser. No. 08/096,039 now abandoned and Ser. No. 08/250,162, now U.S. Pat. No. 5,610,013 both of which are incorporated by reference, non-related TRAP precursor GAGE is also disclosed.
The work which is presented by the papers, patent, and patent applications cited supra deal, in large part, with the MAGE family of genes, and the unrelated BAGE, GAGE and DAGE genes, showing that there are different, additional tumor rejection antigen precursors expressed by cells.
It has now been found that there is yet another family of tumor rejection antigen precursor genes. These nucleic acid molecules show homology to the MAGE family of genes, but this homology is insufficient to identify the members of the MAGE-B family by hybridization with the members of the MAGE-A family, as set forth in, e.g., PCT Application PCT/US92/04354 and U.S. Pat. No. 5,342,774, under the conditions of stringency set forth therein. Further, the isolated nucleic acid molecules of the invention were all found on the Xp arm of the X chromosome, as contrasted to the previously identified members of the MAGE-A family, all of which were found on the Xq arm. Thus, the invention relates to isolated nucleic acid molecules which encode for MAGE-B tumor rejection antigen precursors and the uses thereof.
The invention is explained in further detail in the disclosure which follows.